The present disclosure relates to image processing apparatuses.
When an image processing apparatus such as a scanner reads an image, if a document is placed on a platen glass in a skewed state, or a document is skewed in the case of the document being fed by an automatic document feeder (ADF), a read document image may be skewed.
A certain image processing apparatus detects an edge position along a main scanning direction and a sub-scanning direction, specifies an edge of a document image on the basis of the edge position, and detects a skew of the document image on the basis of the edge.
Another image processing apparatus has a background medium having a color different from a background color of a document, detects a position of a corner point of a document image in a scanned image, and detects a skew of the document image on the basis of the position of the corner point.